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Biomedical subjects

M Beck

Publications and source records attributed to M Beck.

At least 127 records · Page 7Linked to original sources
PubMed2000

Effect of systemic penicillin on pain in untreated irreversible pulpitis.

OBJECTIVE: The purpose of this prospective, randomized, double-blind study was to determine the effect of penicillin on pain in untreated teeth diagnosed with irreversible pulpitis. STUDY DESIGN: Forty emergency patients participated, and each had a clinical diagnosis of an irreversible pulpitis. Patients randomly received a 7-day oral dose (28 capsules, 500 mg each, to be taken every 6 hours) of either penicillin or a placebo control in a double-blind manner. No endodontic treatment was performed. Each patient also received ibuprofen; acetaminophen with codeine (30 mg); and a 7-day diary to record pain, percussion pain, and number and type of pain medication taken. RESULTS: The administration of penicillin did not significantly (P >.05) reduce pain, percussion pain, or the number of analgesic medications taken by patients with untreated irreversible pulpitis. The majority of patients with untreated irreversible pulpitis had significant pain and required analgesics to manage this pain. CONCLUSION: Penicillin should not be prescribed for untreated irreversible pulpitis because penicillin is ineffective for pain relief.

Adult↗
PubMed2000

Free nerve endings in the ligamentum capitis femoris.

We report the presence of free nerve endings (FNE) in the ligamentum capitis femoris (LCF). Qualitative and quantitative measurements on the incidence of FNE, as assessed by immuno-histochemistry for the S-100 protein, were obtained from 18 patients undergoing hip surgery. We found FNE in all LCF, with no association to age. The presence of FNE in the LCF suggests a role in noci-/proprioception of the hip.

Adolescent↗
PubMed2000

A phase I/II trial of recombinant methionyl human brain derived neurotrophic factor administered by intrathecal infusion to patients with amyotrophic lateral sclerosis.

BACKGROUND: Brain derived neurotrophic factor (BDNF) is a potent survival factor for motoneurons. This study investigated the safety and tolerability of recombinant methionyl human BDNF (r-metHuBDNF) infused intrathecally by means of an implanted pump in patients with ALS. METHODS: Twenty-five patients with probable or definite ALS were treated with either r-metHuBDNF (25, 60, 150, 400 or 1000 microg/day) or placebo in a 12-week, randomized, double-blinded, sequential, dose-escalation study. Test treatment was interrupted by a washout period from days 11 to 25 to allow the evaluation of laboratory safety measures. In each dose cohort four patients received r-metHuBDNF and one received placebo. On completion of the double-blind period of the study all patients continued to receive r-metHuBDNF in an open-label extension for up to 60 weeks. Lumbar cerebrospinal fluid (CSF) samples were taken periodically from all patients for the measurement of r-metHuBDNF levels and in a minority of patients these were supplemented by cistemal samples. RESULTS: Within days after the initiation of infusion the majority of patients receiving r-metHuBDNF reported mild sensory symptoms, including paraesthesias or a sense of warmth, which were usually confined to the lower limbs and were frequently exacerbated by neck flexion. In most instances these symptoms decreased or even disappeared over several weeks. Sleep disturbance, dry mouth, agitation and other behavioural effects were encountered at higher doses (>150 microg/day) and necessitated dose reductions. The spinal CSF levels of r-metHuBDNF were directly related to dose, with a lumbar to cervical ratio of approximately 4:1. CONCLUSIONS: The intrathecal delivery of r-metHuBDNF in doses of up to 150 microg/day was well tolerated and appears feasible. The reversible CNS effects with higher dose indicate that BDNF can be delivered cranially against CSF flow. The small number of patients and the design of the study did not permit conclusions to be drawn about the efficacy of the treatment.

Adult↗
PubMed2000

Laying hen behavior 2. Cage type preference and heterophil to lymphocyte ratios.

Studies were conducted to determine hen preference for and stress response to cage type. By using a plywood (1.25 cm) test apparatus with open- and solid-sided compartments and a plexiglass divider at the entrance for controlling passage, birds (n = 20) were evaluated as to their choice of compartment after training and acclimation. For each test, after training, an individual bird was placed in the start box and given 1 min to acclimate before making a choice. The experiment was repeated after rotating the apparatus 180 degrees. In Experiment 1, the open-sided compartment was chosen by 45% of the hens, and the solid-sided compartment by 25% (P = 0.02); 30% chose neither. In Experiment 2, the compartment with open sides was chosen by 70% of the hens, and that with solid sides was chosen by 15% (P = 0.004); 15% chose neither. The length of time required to choose one compartment over the other did not differ in either experiment (P = 0.29; P = 0.76). In Experiment 3, tests were videotaped from 0830 h to 1330 h, and tapes were scored for time spent in each compartment. Birds were observed to spend more time in open- compared with solid-sided compartments (P = 0.02). To assess stress level of birds exposed to each type of enclosure, blood was collected from 24 commercial Hy-Line W36 hens housed long-term in either open (n = 12) or solid (n = 12) cages, and heterophil:lymphocyte (H:L) ratios were determined. Birds in solid cages had higher H:L ratios than did birds in open cages (P = 0.02), indicating a greater stress response. These data would suggest that hens may prefer greater visual access to their surroundings afforded by open cages.

Animals↗
PubMed2000

Induction of interleukin-1alpha production in murine Sertoli cells by interleukin-1.

In the present study we examined the involvement of interleukin (IL)-1alpha, -1beta, FSH, and lipopolysaccharide (LPS) in the regulation of IL-1alpha and -1beta production by Sertoli cells under in vitro conditions. Sertoli cell cultures from immature mice produced constitutively basal levels of intracellular IL-1alpha. Stimulation of Sertoli cell cultures with LPS (5 microgram/ml) resulted in a maximal production of intracellular IL-1alpha 2 h after the stimulation. Thereafter, these levels decreased but remained significantly higher within 24 h after stimulation than those in control cultures. The effect of LPS on IL-1alpha production was dose dependent. FSH did not show any effect on intracellular IL-1alpha production by Sertoli cells. IL-1alpha could not be detected in supernatants of unstimulated or stimulated Sertoli cell cultures. Sertoli cell cultures stimulated with recombinant IL-1alpha induced optimal intracellular levels of IL-1alpha within 2 h of stimulation. These levels remained high 24 h after stimulation. However, stimulation of Sertoli cell cultures with IL-1beta induced a peak of IL-1alpha production 8 h after stimulation. These levels decreased 24 h after the stimulation but were still found to be significantly higher than those in control cultures. The addition of IL-1 receptor antagonist (IL-1ra) to Sertoli cell cultures did not significantly alter their capacity to produce IL-1alpha. However, the stimulatory effects of recombinant IL-1alpha on IL-1alpha production by Sertoli cell cultures were reversed by the concomitant addition of recombinant IL-1ra. No immunoreactive IL-1beta could be detected in lysates or conditioned media of immature murine Sertoli cells under any of the stimulatory conditions outlined. Our results may suggest the involvement of physiological (IL-1) and pathophysiological factors (LPS) in the regulation of spermatogenesis and spermiogenesis processes and male fertility.

Animals↗
PubMed2000

Pain reduction in untreated irreversible pulpitis using an intraosseous injection of Depo-Medrol.

The purpose of this prospective, double-blind, randomized study was to evaluate pain reduction using an intraosseous injection of slow-releasing methylprednisolone in teeth with irreversible pulpitis. Forty subjects presenting for emergency treatment completed the study. Each subject had a tooth with a clinical diagnosis of irreversible pulpitis with actively associated moderate to severe pain. After local anesthesia was attained, the subjects were randomly assigned to receive an intraosseous injection of either 1.0 ml of Depo-Medrol (40 mg) or 1.0 ml of sterile saline (control). No endodontic therapy was begun at the initial appointment. The subjects received ibuprofen and Tylenol #3 and completed a 7-day questionnaire on pain, percussion pain, and analgesic medications taken each day. Over the 7-day observation period, the subjects who received the intraosseous injection of Depo-Medrol reported significantly (p < 0.05) less pain and percussion pain while taking significantly (p < 0.05) fewer pain medications. Clinically the intraosseous injection of Depo-Medrol could be used to temporarily alleviate the symptoms of irreversible pulpitis until definitive treatment can be rendered.

Acetaminophen↗
PubMed2000

Injections of botulinum toxin A into the salivary glands improve sialorrhoea in amyotrophic lateral sclerosis.

Sialorrhoea is a socially disabling problem in bulbar amyotrophic lateral sclerosis (ALS). Botulinum toxin A (BoNT/A) was injected into the salivary glands in five patients with bulbar ALS and sialorrhoea. The effect of BoNT/A was measured by the number of paper handkerchiefs used each day and by salivary gland scintigraphy. BoNT/A ameliorated sialorrhoea and quality of life without major adverse effects. BoNT/A may be a relatively safe and effective treatment for sialorrhoea in selected patients.

Aged↗
PubMed2000

Interleukin-1 receptor antagonist is produced by sertoli cells in vitro.

The interleukin-1 (IL-1) system has been suggested to be involved in the cell-to-cell cross-talk within the testis. To identify a testicular cell source of IL-1 receptor antagonist (IL-1ra), mouse Sertoli cells were isolated, purified, cultured, and examined for IL-1ra. Our investigation revealed that Sertoli cells produce large amounts of immunoreactive IL-1ra under basal culture conditions, as examined by enzyme-linked immunosorbent assays. Its expression can be induced, showing maximum concentrations after 8 h of stimulation. Lipopolysaccharide, as well as IL-1alpha and -beta, were found to stimulate IL-1ra production in Sertoli cells. FSH is capable to induce IL-1ra production in Sertoli cells in a dose-dependent manner. Immunocytochemical staining confirmed the presence of IL-1ra in the cytoplasma of Sertoli cells. The presence of IL-1ra messenger RNA was demonstrated by RT-PCR analysis. Our results may help to better evaluate the IL-1 activity in the testis and may indicate the involvement of IL-1ra in the autocrine and paracrine regulation of testicular cell function.

Animals↗
PubMed2000

The anatomy and function of the gluteus minimus muscle.

In order to investigate the functional anatomy of gluteus minimus we dissected 16 hips in fresh cadavers. The muscle originates from the external aspect of the ilium, between the anterior and inferior gluteal lines, and also at the sciatic notch from the inside of the pelvis where it protects the superior gluteal nerve and artery. It inserts anterosuperiorly into the capsule of the hip and continues to its main insertion on the greater trochanter. Based on these anatomical findings, a model was developed using plastic bones. A study of its mechanics showed that gluteus minimus acts as a flexor, an abductor and an internal or external rotator, depending on the position of the femur and which part of the muscle is active. It follows that one of its functions is to stabilise the head of the femur in the acetabulum by tightening the capsule and applying pressure on the head. Careful preservation or reattachment of the tendon of gluteus minimus during surgery on the hip is strongly recommended.

Aged↗
PubMed2000

The British offshore oil industry after Piper Alpha.

In 1998, the explosion of the Piper Alpha platform claimed 167 lives, making it the world's worst offshore oil disaster. Following this disaster, the U.K. offshore regulatory regime underwent a fundamental reconstruction which was based on the principles of self-regulation and goal-setting. This article argues that there has been no clearly discernable pattern of improvement in terms of offshore incidents since the post-Piper Alpha reforms. The authors attribute this lack of improvement to three principal factors, namely, the lack of effective workforce participation and representation in safety matters, the oil industry's strategic use of "veto points" and, lastly, the failure of the new regulator to police offshore safety and to adequately deter rogue operators.

Journal Article↗
PubMed2000

Abnormal fatty acid composition in umbilical cord blood of infants at high risk of atopic disease.

UNLABELLED: It is well known that patients with atopic disease have anomalies of fatty acid composition in their blood. The aim of the present study was to evaluate whether infants from atopic families also have abnormal cord blood levels of long-chain polyunsaturated fatty acids (LC-PUFA) in plasma and red blood cells. The levels of LC-PUFA in umbilical cord blood of 50 healthy, full-term infants with a hereditary risk of atopic disease were analysed and compared with a control group of 50 infants from families without a history of atopic disease. The atopy group was comprised of children from families suffering from atopic dermatitis, allergic rhinitis, asthma bronchiale and food allergy. Within this group, a group (n = 11) was formed in which the risk was determined only by paternal atopy. Fatty acids of plasma and red blood cell phospholipids, triglycerides and sterol esters were separated by high-resolution gas-liquid chromatography. In particular, the levels of arachidonic acid (C20:4n-6) and docosatetraenoic acid (C22:4n-6) were significantly lower in infants at risk of atopic disease than in infants not at risk. Interestingly, there were more significant differences shown between the control group and the paternal atopy group than between the control group and the entire atopy group. CONCLUSION: The results of this study could be due to a genetic influence of fatty acid metabolism or could reflect the different dietary behaviours of the mothers during pregnancy.

Case-Control Studies↗
PubMed1999

Distinct phosphatidylinositol 3-kinase lipid products accumulate upon oxidative and osmotic stress and lead to different cellular responses.

Signaling by phosphatidylinositol (PI) 3-kinases is mediated by 3-phosphoinositides, which bind to Pleckstrin homology (PH) domains that are present in a wide spectrum of proteins. PH domains can be classified into three groups based on their different lipid binding specificities. Distinct 3-phosphoinositides can accumulate upon PI 3-kinase activation in cells in response to different stimuli and mediate specific cellular responses. In Swiss 3T3 mouse fibroblasts, oxidative stress induced by 1 mM H(2)O(2) caused almost exclusive accumulation of phosphatidylinositol 3,4-bisphosphate (PtdIns(3, 4)P(2)), whereas osmotic stress increased both phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P(3)) and PtdIns(3,4)P(2) levels. The increase in PtdIns(3,4)P(2) levels, caused by oxidative stress, correlated with the activation of protein kinase B, which has a promiscuous PH domain that binds both PtdIns(3,4,5)P(3) and PtdIns(3, 4)P(2). p70 S6 kinase, another signaling component downstream of PI 3-kinase, however, was not activated by this oxidative stress-induced increase in PtdIns(3,4)P(2) levels. Increased PtdIns(3,4,5)P(3) and PtdIns(3,4)P(2) levels in response to osmotic stress did not correlate with protein kinase B activation, because of concomitant activation of an inhibitory pathway, but p70 S6 kinase was activated by osmotic stress. These results demonstrate that PtdIns(3,4)P(2) can accumulate independently of PtdIns(3,4, 5)P(3) and exerts a pattern of cellular responses that is distinct from that induced by accumulation of PtdIns(3,4,5)P(3).

3T3 Cells↗
PubMed1999

Phylogenetic diversity of the expression of the microtubule-associated protein tau: implications for neurodegenerative disorders.

The microtubule-associated protein tau regulates the dynamic stability of the neuronal cytoskeleton by interacting with microtubules. It is encoded by a single gene, but expressed in a variety of isoforms due to differential RNA splicing. Six isoforms can be found in the human central nervous system. These isoforms differ in their ability to promote the assembly of microtubules as well as in their capacity to stabilize existing microtubule structures. Furthermore, some of the isoforms of tau are specifically involved in the pathogenesis of neurodegenerative disorders. Thus, splicing of tau might critically influence the physiological functions of tau protein as well as the pathogenesis of neurodegenerative diseases with tauopathy. The present study addresses the differential expression of the six isoforms of tau in the central nervous system of 12 mammalian species including Homo sapiens. The occurrence of each of the six tau isoforms was highly variable. However, species that were phylogenetically related expressed a similar pattern of tau isoforms. These results suggest a phylogenetic descent of splicing paradigms, which can be matched with known phylogenetic concepts based on morphological and molecular genetical studies. Especially, the unique expression pattern of tau isoforms in the human central nervous system implicates a possible link to the particular vulnerability of humans to neurodegenerative disorders with tauopathy, namely Alzheimer's disease, frontotemporal dementia and Pick's disease.

Animals↗
PubMed1999

Comparison of maximal voluntary isometric contraction and Drachman's hand-held dynamometry in evaluating patients with amyotrophic lateral sclerosis.

Maximal voluntary isometric contraction (MVIC) is a standard tool for assessment of muscle strength in treatment trials for amyotrophic lateral sclerosis (ALS). There is need for more practical bedside techniques especially for severely disabled patients. Hand-held dynamometry (HH-Dyn) is an inexpensive and easy-to-handle device. MVIC was measured in five proximal muscle groups bilaterally and compared with HH-Dyn in 43 ALS patients. After a training period we found good intrarater correlation for HH-Dyn (r = 0.99), with a low coefficient of variation. Measurements tended to become more accurate after repeated testing due to practice effects in examiners and patients. Overall correlation between HH-Dyn and MVIC was good [r = 0.85 (P < 0.01)]. Strength-range-specific analysis showed a significant linear correlation up to 20 kg (44 lbs.) [r = 0.57 (P < 0.01)]. However, we found a tendency to underestimate muscle strength above 10 kg by HH-Dyn as compared with MVIC, but this became meaningful only above a force of 20 kg. HH-Dyn provides a strength estimate with a precision close to MVIC in weak muscle groups (MRC grade 4). With standardization and appropriate training, HH-Dyn is a useful bedside test, providing an alternative to MVIC for follow-up assessment in ALS.

Adult↗
PubMed1999

[Clenbuterol in amyotrophic lateral sclerosis. No indication for a positive effect].

The anabolic effects of clenbuterol have been recognized for a long time. Clenbuterol augments the expression of specific muscle proteins with a differential effect on type I and type II fibres. Furthermore, clenbuterol induces the synthesis of endogenous nerve growth factor (NGF) and may itself be a myotrophic factor released by neuron endings. Side effects include tremor and headache and dose dependent abnormalities of laboratory values (hypokalemia, hypoglycemia). After long-term medication increasing fatigue of muscles has been observed. Decreased expression of beta 2-adrenergic receptors may limit the expected functional improvement. The efficacy of clenbuterol as symptomatic treatment of amyotrophic lateral sclerosis has not been proved. Controlled treatment trials are warranted to assess this question.

Adrenergic beta-Agonists↗
PubMed1999

A maternal gene mutation correlates with an ovary phenotype in a parthenogenetic wasp population.

Endoparasitoid wasps rely on maternal protein secretions, including viruses and virus-like particles (VLPs), to overcome host defense reactions. In the ichneumonid Venturia canescens, VLPs are assembled in the nuclei of ovarian calyx gland cells, secreted into the lumen of the gland, and eventually transmitted into the host caterpillar together with the parasitoid egg. One of the genes coding for VLP proteins, termed VLP1, exists in two alleles producing two structurally different proteins. Here we describe the establishment and initial phenotypic characterisation of two parthenogenetic laboratory strains, which differ in VLP1 as well as in other genetic markers. A comparison of calyx tissues from the two strains revealed morphological differences that seem to affect egg movement from the ovarioles into the oviduct. The observed histological changes are correlated with differences in egg maturation and embryonic development causing a delay in larval hatching in one of the strains. Under conditions that favour superparasitism, the two strains differ in the number of offspring produced.

Amino Acid Sequence↗